1. Field of the Invention
The present invention relates to a gear matching device which performs gear matching so as to establish a rotational phase relationship between a rotary tool and a gear to be machined in which the rotary tool and the gear can mesh with each other, and also relates to a gear machining apparatus using the gear matching device.
2. Description of the Related Art
Gear machining apparatuses, such as gear grinders and hobbing machines, have heretofore been offered as tools for machining gears by using rotary tools. In such a gear machining apparatus, a rotary tool and a gear to be machined (hereinafter referred to simply as a “gear” in the description) are synchronously controlled respectively by separate drive motors, and gear machining is then performed by causing the rotary tool and the gear to mesh with each other.
In addition, in the gear machining apparatus, a “gear matching” process is performed before the rotary tool and the gear are caused to mesh with each other. The gear matching process is performed so as to establish a rotational phase relationship between the rotary tool and the gear in which tooth tips (crests) and tooth spaces (troughs) of the rotary tool can mesh with tooth tips (crests) and tooth spaces (troughs) of the gear. In this gear matching process, the rotational phases respectively of the rotary tool and the gear are firstly detected by using a contact sensor such as a touch probe, or a non-contact sensor such as a proximity sensor. On the basis of the detection results, the offset between these rotational phases is corrected, so that the rotational phase of the rotary tool and the rotational phase of the gear are adjusted.
For example, Patent Document 1 discloses such a gear matching device. In this gear matching device, a tooth tip and a tooth space of a gear are read by using a sensor, while the rotations respectively of the rotary tool and the gear are determined. As a result, gear matching can be performed.    Patent Document 1: Japanese Patent Application Laid-open Publication No. 2004-25333